(1) Field of the Invention
The invention relates to a method of forming an integrated circuit, and more particularly, to a method of reducing noise by forming a Schottky diode underlying passive components in the manufacture of integrated circuits.
(2) Description of the Prior Art
In the manufacture of integrated circuits, circuits such as radio frequency (RF) circuits have many passive components; for example, inductors and metal-insulator-metal (MIM) capacitors. These passive components require a high quality factor, but they often suffer from noise originating from the substrate. The magnetic effect from the substrate to an inductor is one major source of noise which degrades the inductor""s performance. Many process engineering procedures have been used to protect inductors and other components from noise, but these processes are usually quite complicated.
U.S. Pat. Nos. 5,445,985 to Calviello et al, 5,268,315 to Prasad et al, and 5,450,263 and 5,370,766, both to Desaigoudar et al show methods of forming inductors and Schottky diodes. U.S. Pat. No. 4,577,213 to Bauhahn shows a Schottky barrier beam lead diode. U.S. Pat. No. 6,100,770 to Litwin et al teaches a method of forming a high quality varactor.
A principal object of the present invention is to provide an effective and very manufacturable method of forming high quality passive components in the fabrication of integrated circuit devices.
Another object of the invention is to provide a method of fabricating passive components having reduced noise in the manufacture of integrated circuits.
Yet another object of the invention is to provide a method of fabricating high quality passive components having reduced capacitive and magnetic effect in the manufacture of integrated circuits.
A further object is to provide a method of fabricating high quality passive components having reduced capacitive and magnetic effect by using a Schottky diode underlying the passive components.
A still further object is to provide a method of fabricating a high quality inductor having reduced magnetic effect from the substrate by using a Schottky diode underlying the inductor.
A yet further object is to provide a method of fabricating a high quality capacitor having reduced capacitive effect from the substrate by using a Schottky diode underlying the capacitor.
Yet another object of the invention is to provide an integrated circuit device with high quality passive components having reduced capacitive and magnetic effect in the manufacture of integrated circuits.
A further object is to provide an integrated circuit device with high quality passive components having reduced capacitive and magnetic effect because of the presence of a Schottky diode underlying the passive components.
A still further object is to provide an integrated circuit device with a high quality inductor having reduced magnetic effect from the substrate because of the presence of a Schottky diode underlying the inductor.
A yet further object is to provide an integrated circuit device with a high quality capacitor having reduced capacitive effect from the substrate because of the presence of a Schottky diode underlying the capacitor.
In accordance with the objects of this invention a method of fabricating high quality passive components having reduced capacitive and magnetic effects by using a Schottky diode underlying the passive components in the manufacture of integrated circuits is achieved. A Schottky diode is formed completely covering the active area where passive components will be formed. The Schottky diode is covered with a dielectric layer. Passive components-are formed overlying the dielectric layer wherein the Schottky diode reduces substrate noise resulting in high quality of the passive components.
Also in accordance with the objects of the invention, an integrated circuit device with high quality passive components having reduced capacitive and magnetic effect because of the presence of a Schottky diode underlying the passive components is achieved. A Schottky diode completely covers an active area of a substrate. A dielectric layer overlies the Schottky diode. Passive components overlie the dielectric layer. The Schottky diode reduces substrate noise resulting in high quality of the passive components.